Disclaimer: I'm a founder of an early stage startup, so I'm biased. You need to figure out what your goals are. We can't answer for you because we don't know what you want. If your goal is just money (which is fine, don't be afraid to say this), then definitely go to google. In 10 years you'll be earning 500k per year, and have put away a ton of cash too. Financially, if the startup is successful you_might_ make $10m…
I'm somewhat bothered by your comment about money:
> If your goal is just money (which is fine, don't be afraid to say this), then definitely go to google.
I find this disingenuous, as money is also a big reason why people do startups, both the employees and the founders. The founders could have chosen to implement their idea inside Google or wherever (with an army of marketing, virtually unlimited funding as long as the idea is working out, and all forms of support to bolster the team and the product), but the founder passed on that in order to reap the huge rewards that come with owning a successful company. Or, in order to have "personal" control (inasmuch as you can have that when you still have investors, a Board, and an indifferent target audience).
Sure, there are _some_ founders whose vision genuinely doesn't fit inside any FANG... but those are the exception. For most visions, the best possible way to realize them is inside BigCo.
Also, the promise of a Google-sized payday is hinted at to employees ("Join us... we think this is a Google-sized opportunity" is a common thing founders say). Even your own statement ("you _might_ make $10m, but that's unlikely") embodies the dream and the challenge presented to a prospective employee who's ready for a big risk, to put their guarantees and expected-outcomes on the line for that sweet $10m.
The prospective employee probably doesn't realize that the founders who are pitching them on .01% still hold 60% between the two of them, and a different class of shares. The prospective doesn't realize that there is only an infinitesimally, vanishingly small likelihood they'll make even close to what they'll make at the big company.
But even when the employees make very little, the founders still have a good path to making bank, in the case of even a minor acquisition or an acquihire.